This plugin is very smart, light and solid, better than AuthMe or XAuth
it is essential and don't allow users to have any other permission they can only register (if they aren't) or login (if they are not logged in)

commands & permissions:
commands:
login:
description: login.
permission: solidlogin.basic
usage: /login <password>
register:
description: register.
permission: solidlogin.basic
usage: /register <password> <password>
changepwd:
description: change your current password with a new one.
permission: solidlogin.basic
usage: /changepwd <password> <password>

permissions:
solidlogin.basic:
default: true
solidlogin.admin:
default: false

Note:
who owns permission "solidlogin.admin" (or by console)
can change password using: /changepass <player> <pass> <pass>